Phase I studies are pharmacology and toxicity studies in humans of new anti-cancer agents that have already had preclinical toxicity, pharmacology and anti-tumor activity testing completed. These studies usually require 20-30 patients with refractory malignant disease. Initial dosages are picked based on toxicity data from laboratory animals. Dosages are escalated according to standard schemes. Three patients are treated at each non-toxic dose level and 6 patients at each level with reversible acceptable toxicity. When dose limiting toxicity is encountered the study is closed. The result of these projects indicate: 1) the MTD of AMSA when given as a single dose every two weeks is 70 mg/m squared and 120 mg/m squared when given as a single dose every 3 weeks. 2) the MTD for PALA when given daily for 5 consecutive days is 1500 mg/m2. 3) the MTD for PMM when given as a single dose every 3 weeks has yet to be defined but will exceed 1.0 gr/m2.